1 files changed, 42 insertions, 0 deletions
diff --git a/internal/frontend/experiments_test.go b/internal/frontend/experiments_test.go
new file mode 100644
index 00000000..cb28013e
--- /dev/null
+++ b/internal/frontend/experiments_test.go
@@ -0,0 +1,42 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package frontend
+
+import (
+	"context"
+	"sort"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"golang.org/x/pkgsite/internal/experiment"
+)
+
+func TestNewContextFromExps(t *testing.T) {
+	for _, test := range []struct {
+		mods []string
+		want []string
+	}{
+		{
+			mods: []string{"c", "a", "b"},
+			want: []string{"a", "b", "c"},
+		},
+		{
+			mods: []string{"d", "a"},
+			want: []string{"a", "b", "c", "d"},
+		},
+		{
+			mods: []string{"d", "!b", "!a", "c"},
+			want: []string{"c", "d"},
+		},
+	} {
+		ctx := experiment.NewContext(context.Background(), "a", "b", "c")
+		ctx = newContextFromExps(ctx, test.mods)
+		got := experiment.FromContext(ctx).Active()
+		sort.Strings(got)
+		if !cmp.Equal(got, test.want) {
+			t.Errorf("mods=%v:\ngot  %v\nwant %v", test.mods, got, test.want)
+		}
+	}
+}